Google Sites, primarily YouTube, Facebook, and music-video site VEVO snagged the largest share of online video watchers. Google Sites brought in over 150,000 unique viewers in December , making it easily the number one source for online videos, followed by Facebook, which brought in almost 60,000 unique viewers last month.

Online video ads accounted for more than a fifth of all videos viewed last month, with more than 11.3 billion ads being watched in total.

Unsurprisingly, two billion of those video ads were viewed on Google Sites. Online ad platform BrightRoll dished out over 1.8 billion online video ads in December, while LiveRail.com, Hulu, and Adap.TV followed closely behind.

When it comes to the number of ads an individual viewer sees, Hulu beats the competition, delivering, on average, 65 advertisements per use last month.

The latest statistics by comScore also found that the average online video clocks in at around 5.4 minutes, while the average duration of a video ad online is a little less than 30 seconds.